The purpose of this study was to prevent from chronic diseases such as coronary heart disease by using swimming program for elder & middle-aged women, and to investigate the effects of serum lipids. The subjects classified into trained elderly women group(60-65 yeas, n=8), untrained elderly women group(60-65 years, n=8), trained middle-aged women group(42-48 years, n=8), & untrained middle-aged women group(42-48 years, n=8). In order to change of the acurate serum lipids by swimming program during 8 months(3times/week, 50min./day), all subjects of each group were gradually exercised by treadmill untill exhaustion. Blood samples were taken from antecubital vein one time immediately after exhaustion and analyzed for total cholesterol, HDEL-cholesterol, triglycerides, and LDL-cholesterol calculated by the formula of Friedewald et al. These data were analyzed by twoway ANOVA between age(aged females * middle-aged females) * training(trained * untrained) groups. The results showed that there were significant changes in total cholesterol at age groups(p< 0.05), but no significant changes at training groups(p >0.05) & age * training groups interaction(p>0.05). and there were significant changes in HDL-cholesterol(age groups, p<0,01: training groups, p< 0.001, age * training groups interaction, p >0.05), triglycerides(age groups, p<0.01: training groups, p< 0.001, age * training groups interaction, p >0.05), and LDL-cholesterol(age groups, p<0.01: training groups, p< 0.001, age * training groups interaction, p >0.05). In conclusion, increases in HDL-cholesterol and decreases in LDL-cholesterol & triglycerides after endurance training can be suggested as an effect to prevent CHD for the elderly & middle-aged subjects.